Explanation

The Sokoto Caliphate (1804-1903) was founded by Usman dan Fodio through jihad against corrupt Hausa rulers. It became the largest state in 19th century Africa.

Structure: Sultan as religious and political leader, emirates governed by appointed emirs, sharia law, Islamic education promoted. It reformed society along Islamic principles.

Legacy: unified northern Nigeria, established emirate system still influential today, spread literacy and Islamic scholarship, created administrative structures the British later adopted.